1. Field of the Invention
The present invention relates to damping of vibration of hollow handle object striking implements such as hammers and other tools, and, more particularly, to sports object striking implements such as bats for baseball, softball and youth play. Such bats are typically made of a metal outer shell formed of aluminum or titanium alloy or other metals.
2. Prior Art
Systems for damping of vibrations in implements such as metal shell bats include what can be generally referred to as tuned mass systems and cushion mass systems. Tuned mass vibration systems employ a moveable object such as a vibration damping pendulum located in a hollow cavity within the bat or other implement which is sized, positioned and frequency matched or tuned to swing within the cavity without contacting the walls of the cavity to effectively damp vibrations incurred when the implement strikes an object. Cushion mass systems employ elastomeric or foam cushions positioned within a cavity in the implement which resiliently come into contact with the walls of the cavity to reduce the amplitude of vibration transferred through the handle of the implement to the user""s hand or hands. Since tuned mass vibration damping systems react somewhat more slowly than cushion mass systems due to inertia of the tuned mass, tuned mass systems are the dampers of choice for damping steady state vibration whereas cushion mass dampers are more frequently employed for damping impact induced vibrations.
The primary objective of the invention is to provide an object striking implement with improved vibration damping of the handle.
The present invention provides an object striking implement having a tubular handle, an object striking portion affixed to said handle and a vibration damper having a support portion affixed in said handle and a resilient damping portion flexibly connected to the support portion. The damping portion is arcuately moveable inwardly of said handle in a direction generally transverse to a longitudinal axis of said handle and is compressible to cushion contact of the damping portion with said handle. The damper therefore functions with some of the characteristics of both tuned mass and cushion mass damping systems.
The vibration damper may be made entirely of resilient material having an undistorted shape and a distorted shape which differs from the undistorted shape when the damper is positioned in the handle.